DE1543747B2 - Process for the preparation of bisquaternary alkyl ammonium sulfate salts - Google Patents

Description

The invention relates to a process for the preparation of bisquaternary alkyl ammonium sulfate salts by reacting a dialkyl sulfate ester, the alkyl groups of which can contain 1 to 8 carbon atoms, with a trialkylamine, the alkyl groups of which can contain 1 to 8 carbon atoms. It is known that the reaction between a dialkyl sulfate ester _{and a trialkylamine leads to a quaternary ammonium alkyl sulfate salt of the general formula R 3 RZNOSO 3} R ', in which R and R' are identical or different alkyl radicals. (Houben-Weyl, Methods of Organic Chemistry, Vol. XI / 2 [1958], pp. 592 to 508, German Patent 545 430 and British Patent 509 542.) The direct Her- _; formation of a bisquaternary ammonium sulfate salt, (R ₃ R'N) ₂ SO ₄ , in which R 'are identical or different alkyl radicals; from a: dialkyl sulfate ester ^. and a trialkylamine, on the other hand, is unknown.

The object of the invention was therefore to find a process for the direct production of a bisquaternary ammonium sulfate salt from a dialkyl sulfate ester and a trialkylamine. The process is characterized in that the trialkylamine in a stoichiometric excess in an inert solvent with the dialkyl sulfate is either ^! 100 to 200 "C under a pressure at which the evaporation of the trialkylamine is prevented, or in a first stage at 0 to 50 ⁰ C under atmospheric pressure and then in a second stage at 50 to 400 ⁰ C under a pressure at which the Evaporation of the trialkylamine is prevented, reacts within 0.25 to 3.0 hours.

According to the batch embodiment of the process of the invention, a dialkyl sulfate ester is used and a trialkylamine placed in a reaction vessel capable of being heated under pressure. These reactants are then reacted at a substantially constant temperature held for 0.25 to 3.0 hours, although a reaction of 0.5 to 1.0 hours is generally sufficient is. The pressure in the reaction vessel is maintained so that evaporation of the amine in the respective reaction temperature is prevented. The reaction temperature can range from 50 to 400 ° C, depending on the product to be manufactured. A preferred temperature range is at 100 to 200 ° Α When the molecular weight of the desired bisquaternary ammonium sulfate salt increases, Both the reaction temperature and the reaction time must be increased. For example the reaction between dimethyl sulfate and trimethylamine can take place at a lower reaction temperature and a shorter reaction time than the reaction between dipropyl sulfate and tripropylamine.

The hydrolysis of the sulfate ester takes place at elevated temperatures. Such hydrolysis leads to a lowering of the product yield and to contamination of the end product. It has now been found that the hydrolysis of sulfate ester can be reduced to a minimum if a quaternary group (—O — NR ₃ R ') is formed at a relatively low temperature (0 to 50 ^° C.). After the formation of the first quaternary group, the reaction temperature is then increased to bring about the formation of the second quaternary group. This elevated temperature is usually between 50 and 400 ° C. The total reaction time in this embodiment is the same (0.25 to 3.0 hours) as described for the first embodiment. The reaction time assigned to the reaction portion at low temperature is usually less than -: or about the same as - the duration of the reaction portion at high temperature.

The ratio of the reactants is not critical. In order to increase the reaction or the reaction rate and to improve the yield, however, a stoichiometric excess of the trialkylamine is generally used in all embodiments of the process according to the invention described here. Optimal results are obtained when the stoichiometric excess of trialkylamine exceeds 10%. The reaction . generally found in a solvent; preferably in water instead. However, any inert solvent in which the reactants and product dissolve is useful. In the process according to the invention, after the reaction has progressed to substantial completion, excess amine from the reaction mass is _: separated off and recovered, usually for reuse as a reactant. In all of the embodiments discussed here, after the excess amine has been removed from the reaction product, it is usually evaporated to dryness or at least concentrated by evaporation. In the continuous embodiment of the process according to the invention are fed dialkyl sulfate ester and trialkylamine a reaction zone j between 50 and 400 ° C maintained at a temperature-\ temperature. The pressure in the reaction zone is sufficient to prevent evaporation of the trialkylamine. The reactants are fed to the reaction zone in separate streams. The size of the reaction zone and the feed rates are adjusted so that the contact time is from 0.25 to 3.0 hours gehal- \ th. '

According to the other embodiment of the process according to the invention, dialkyl sulfate esters; trialkylamine and continuously to a first reactor 'tion zone supplied. The reactants will be

introduced in the form of separate streams. The temperature in this first zone is kept between 0 and 50 ° C. The pressure is: · Maintained sufficiently high to prevent evaporation of the trialkylamine. ; In this i zone: a tetraalkylammonium alkyl sulfate is produced. Sufficient contact time is provided to ensure complete implementation. The reaction product and the unreacted: amine are then continuously fed to a second reaction zone in which a temperature between 50 and 400 ° C. is maintained. The pressure in this second zone is maintained so that evaporation of the trialkylamine at the reaction temperature is avoided. The total reaction time in both zones is between 0.25 and 3.0 hours. ¹ - Many bisquaternary ammonium sulfate salts can be produced by the process according to the invention. Salts in which each alkyl group consists of a saturated aliphatic radical having 1 to 4 carbon atoms are preferably prepared by the process according to the invention. ...-. ■. ·

Some of the bisquaternary ammonium sulfate salts which can be prepared by the process according to the invention are e.g. B. bistetramethylammonium sulfate, Bistriäthylmethylammoniumsulfat, Bisteraäthylammoniumsulfat, Bistrimethyläthylammoniumsulfat _; , Bistetrapropylammonium sulfate. _: .

The following examples illustrate the invention.

; Example 1 ■■■■ '■ "■ - ·· ■ ^;

The example illustrates the batch production of tetramethylammonium sulfate. 1 mole (126.2 g) dimethyl sulfate was added to 4.00 moles (236.4 g) of trimethylamine dissolved in 551.6 g of water. The solution temperature was with the help of a cooling bath at about Maintained 5 ° C. After the reaction was complete, this solution was transferred to a shake bomb and heated to about 180 ° C under autogenous pressure (48.2 atü). After cooling to room temperature it was the reaction solution was removed from the shake bomb, excess trimethylamine was removed by heating the reaction solution removed to about 125 ° C at atmospheric pressure.

The results and conditions of this experiment are summarized in Table I below.

Table I.

feed

Trimethylamine, g 236.4

Trimethylamm, solution concentration, volume percent .. '..' 30

Dimethyl sulfate, g 126.2

Moles of amine / mole of dimethyl sulfate 4.0

working conditions
First stage

Pressure atmospheric temperature, ° C 5

Second step

Pressure, atü 48.2

Temperature, ⁰ C 180

Contact time, 1.5 hours

• - bistetramethylammonium sulfate, g ... 236.0

Trimethylammonium tetramethylammonium sulfate, g 4.3

Tetramethylammonium methyl sulfate,

Bistetrarnethylammonium sulfate

Äusbeute, based on dimethyl-ΐ * ^'r sulphate ^{weight: ..:.} 96.5 ~

I Example 2 :: ^ Λ?:> Ιαν, -.- Λι

1.99 moles (251 g) of dimethyl sulfate were slowly added to an aqueous 'solution of'trimethylamine; given at a concentration of 25 percent by volume. During the addition of the dimethyl sulfate ^, to. . _: The solution was constantly stirred and the temperature kept at 28 to 30 ° C. The "amine to ester molar ratio" was about 2.5: T. The ester was added over a period of one hour. The reaction product was then continuously fed to a steam jacketed reactor, which was operated at about 125.degree The contact time was 1 hour. The reaction product would be removed from the reactor and distilled from excess trimethylamine under atmospheric pressure. The following table summarizes the test results.,. '.':,., '.' ... '.'...'. ·. · .: ...

Tables '"^;'""

Loading; · First stage Second step 35 Dimethyl sulfate, g ...: ^...: :: ■ -. ': / ■ ■' ':,: ■ - :, Mole amine / mole dimethyl ^: -25 \ '■' ■ '■ ■ sulfate working conditions 2.58 40 Temperature, ° C Contact time, hours ... 30th 125 Pressure, atü 1.0 1.0 atmo 12.3 45 Products spherical Bistetramethylammonium : sulfate, g Trimethylammonium tetra- 93.4 470.9 50 methylammonium sulfate, g Tetramethylammonium 0.8 0.2 methyl sulfate, g Bistetramethylammonium 286.6 ■ 11.8 sulfate yield, based 55 on dimethyl sulfate weight 19.2 96.9

Example 3

Dimethyl sulfate and 25.1 percent by volume aqueous trimethylamine were continuously one with a A steam-jacketed reactor kept at about 125 ° C and a pressure of about 12 atü was fed. The feed rates were adjusted so that a molar ratio of 2.5 moles of amine per mole of ester is obtained.

This experiment was carried out twice with contact times of 0.5 and 1.0 hours each, over-

excess amine was removed from each reaction product. In Table III below are the Conditions and the respective results of the two experiments are listed.

Table III

Contact time 1.0 hour 0.5 hours feed 560.7 Dimethyl sulfate, g .418.3 Mole amine / mole dimethyl 2.47 sulfate 2.56 working conditions 12.3 Pressure, atü 12.3 126 Reaction temperature, ° C 124 product Bistetramethylammonium 1036.4 sulfate, g 750.2 Trimethylammonium tetra- 19.2 methylammonium sulfate, g 7.3 Tetramethylammonium 21.7 methyl sulfate, g 39.9 Bistetramethylammonium sulfate yield, based 95.5 on dimethyl sulfate weight 92.7

The reaction temperature rises to above 15 ° C was avoided. The addition of sulfate took 1 hour. The reaction product was brought to room temperature warmed up. This product was then continuously fed to a high pressure reactor. The following table summarizes the conditions and results of this experiment:

• Table IV-

^1st ■ ■. ■. ■. ■ First stage Second step feed Triethylamine, g .... 505 Dimethyl sulfate, g 252 Mole amine / mole dimethyl sulfate 2.5 working conditions Temperature, ° C 10-15 126 Contact time, hours 1.0 1.0 Pressure, atü atmo 17.6 spherical Products Bis-diethylmethyl- ammonium sulfate, g 37.8 425.4 Triethylmethyl ammonium methyl sulfate .. 444.2 184.0

Example 4 £ jj _{e r} fi _nc i _un g represents a new and very effective one

2 moles (252 g) of dimethyl sulfate were slowly becoming processes for the production of bisquaternary ammo

a mixture of 2000 ml of water and 505 g of 35 sodium sulfate salts from easily available, cheap ingredients

Triethylamine, cooled to about 10 ⁰ C, given. The gang materials are available.

Claims (1)

Claim: Process for the preparation of bisquaternary alkyl ammonium sulfate salts by reaction a dialkyl sulfate ester, the alkyl radicals of which can contain 1 to 8 carbon atoms, with a trialkylamine, whose alkyl groups can contain 1 to 8 carbon atoms, characterized in that that the trialkylamine in a stoichiometric excess in an inert solvent with · the dialkyl sulfate either at 100 to 200 ° G under a pressure at which "the? Evaporation of the trialkylamine is prevented, or in a first stage at 0 to 50 ° G below Atmospheric pressure and then in a, · ■. second stage at 50 to 400 ° C under one pressure, in which evaporation of the trialkylamine is prevented, within 0.25 to 3.0 hours implements. 20th